Delivery of GonaCon -Equine to Feral Horses (Equus caballus) Using Prototype Syringe Darts

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Teresa Thompson
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1 National Park Service U.S. Department of the Interior Theodore Roosevelt National Park (THRO) Delivery of GonaCon -Equine to Feral Horses (Equus caballus) Using Prototype Syringe Darts B. McCann 1, D. Baker 2, J. Powers 1, A. DeNicola 3, B. Soars 4, M. Thompson 1 1 National Park Service, 2 Colorado State University, 3 White Buffalo Inc., 4 Pneu-Dart Inc. E X P E R I E N C E Y O U R A M E R I C A

2 Outline Horses at Theodore Roosevelt National Park GonaCon: earlier research and opportunities Remote dart delivery research Results to date Management implications

3 Study Area Theodore Roosevelt NP THRO, ~ 46,000 acres in North Dakota Badlands ecology Fenced perimeter Horses present since 1800s ~130 in 2009 ~150 now ~90 on study

4 GonaCon - Equine Gonadotropin Releasing Hormone (GnRH) Vaccine = GnRH + adjuvant Antibodies to GnRH Remote delivery? Re-vaccination?

Prior Research 2009 2013 single hand vaccination = 2 years moderate contraception (~30% decrease) Safe for mares and neonates No adverse behavior effects observed Consistent injection

5 Prior Research single hand vaccination = 2 years moderate contraception (~30% decrease) Safe for mares and neonates No adverse behavior effects observed Consistent injection site reactions 2013 revaccinate by hand injection 2014 reconfirm safety and behavior observations % effective 2016 ~85% effective Conclusion: Re-immunization increases efficacy

6 Current Research Remote Delivery No reliable remote delivery method Needed a practical application method Objectives Primary: Remote delivery options Secondary: Re-vaccination intervals

7 Current Research Remote Delivery Pneu-Dart Slo-Inject Relatively new technology 3.81cm, 14 ga, Tri-port needle Gel collar 1.27 cm ahead of ferrule

8 Methods 2013 Roundup Darts loaded with ~2.0 ml GonaCon Weighed before and after 11 new mares darted with vaccine

9 Pilot trial

10 Pen Trial

Field - methods 2015-2016 Field Darting Operations Measured speed at target Optimum velocity Consistency between delivery systems

11 Field - methods Field Darting Operations Measured speed at target Optimum velocity Consistency between delivery systems Projector Range (meters) Pressure (bar) Mean velocity (meter/second) Dan-Inject Pneudart Excalibur

12 Study Design Re-immunization schedule darting (sample size) [mean age # ] 6 mo (n = 15) [2.2] (1-14) 1 year (n = 15) [1.6] (1-5) 2 year (n = 11) [2.9] (2-4) 4 year (n = 25)* [5.5] (2-17) Control (n = 25)* [5.1] (2-11) * From the original 2009 cohort # At time of initial vaccination

13 Field Methods Weighing empty Loading dart Weighing loaded Approaching and darting Observing darted animal Collecting dart Weighing fired darts

14 Darting

15 Darting

Field Darting Data Field Darting Observations 2015-2016 88 darts loaded and fired 74 delivered full dose 6 lost 5 delivered

16 Field Darting Data Field Darting Observations darts loaded and fired 74 delivered full dose 6 lost 5 delivered insufficient vaccine 2 bounced out 1 missed 84.1% success rate for delivery of full vaccine payload All animals eventually dosed remotely

Preliminary Contraception Results Contraceptive efficacy - animals darted 2013-2016 6 month 1 year 2 year 4 year (previously reported Baker et al.

17 Preliminary Contraception Results Contraceptive efficacy - animals darted month 1 year 2 year 4 year (previously reported Baker et al. 2018) Fertility prior to darting unknown Compare foaling rates with control (4 yr) Primary vaccination had similar modest decrease 2014 was a tough year and had low foaling rates

24 Preliminary Injection Site Results Injections site reactions are more frequent and more severe. But. May recover more quickly; no lameness observed

Conclusions Dart delivery is feasible for GonaCon -Equine Close range Habituated and identifiable animals Plenty of time Optimal vaccination schedule remains unknown

25 Conclusions Dart delivery is feasible for GonaCon -Equine Close range Habituated and identifiable animals Plenty of time Optimal vaccination schedule remains unknown Preliminary results suggest intervals are similar On-going evaluation return to fertility Injection site reactions may be more severe than hand injection but may resolve more quickly

26 Management Implications Contraception may be an important part of horse management at THRO in the future. Closed, accessible, identifiable, population Management plan and compliance is needed Dart delivery is likely to be the method of choice. Removals may still be needed Ability to remove treated animals important Regulated product is important

Burro Program National Wildlife Research

27 Acknowledgments National Park Service Animal Reproduction and Biotechnology Laboratory, Colorado State University Bureau of Land Management, Wild Horse and Burro Program National Wildlife Research Center Photography by Deb Lee Carson Field research technicians

Reimmunization Increases Contraceptive Effectiveness of GonaCon-Equine Vaccine in Free-Ranging Horses (Equus caballus): Limitations and Side Effects

Reimmunization Increases Contraceptive Effectiveness of GonaCon-Equine Vaccine in Free-Ranging Horses (Equus caballus): Limitations and Side Effects Investigators: D. Baker 1, J. Powers 2, J. Ransom 2,